COLLINS AN/FRT-26

GENERAL DESCRIPTION

AN/FRT-26 HF RADIO TRANSMITTING SET

APPLICATION

The AN/FRT-26 equipment is a 15 kw radio telegraph transmitter for fixed station point-to-point communication in the 4 to 26 megacycle frequency range. Design features include modern circuitry, reliability, simplified adjustments and accessibility.

DESCRIPTION

All radio frequency circuits are contained in the right-hand bay. All power supply circuits except the external high voltage transformer and power control unit are located in the left-hand bay. All controls are electrically interlocked to prevent improper application of power at any time. All rectifier tubes and the high level RF stages are clearly visible through large glass windows. A double width standard 19" equipment rack, 25" high, is located in the lower portion of the transmitter cabinet behind an access door. Mounted on this rack are the servo-amplifiers, excitation equipment and patch panel. No transformer vault or other protective enclosure is necessary for the external equipment. A 10-channel crystal-controlled exciter or a continuously tunable oscillator may be used for excitation. A frequency shift keyer is also available.

Tuning is automatic; following the selection of a desired channel (any one of ten which are preset), servo systems automatically set up the transmitter for operation. No band switching is required, since tuning is continuous over the entire frequency range. Radio transmitting set AN/FRT-26 consists of the following:

Radio transmitter T-454/FRT-26
Power supply assembly PP-1088/FRT-26
Power transformer TF-196/FRT-26
Power control C-1402/FRT-26
RF oscillator 0-270/FRT-26
RF oscillator 0-91/FRT-5
Frequency-shift keyer KY-45/FRT-5
Power supply PP-454/FRT-5

TECHNICAL SPECIFICATIONS
Weight and dimensions Depth Height Width Weight (Total)	37½" 91-9/16" 93¼" 5,070 lb
Frequency range	4.0 to 26.5 mc
Transmitter type	MOPA (Master Oscillator-Power Amplifier)
Crystal type	CR-27/U, with fundamental frequency between 2.0 and 4.2 mc
Types of emission	A1 (on-off keying); F-1 (frequency-shift keying); F-4 (facsimile frequency modulation); or A-3a, A-3b, or A-9c (single-sideband reduced-carrier, duplex independent-sideband reduced-carrier, or composite transmissions) when used with external driving and modulating equipment
Keying speed	400 wpm cw, or 240 dot-cycles per second FSK, maximum
Number of preset frequency channels	10
Number of tubes	87
Ambient humidity	95% maximum
Ambient temperature range	32°F to 122°F
Power source requirements Voltage Frequency Number of phases	230 volts ±10% and 115 volts ±10% 50/60 cps 3
Power output	Normal operation, 15 kw output
Power Factor	Normal operation, 15 kw output: 94.5%
Nominal carrier output	A-1, F-1 or F-4 emission: 15 kw into 600-ohm load with maximum swr (standing wave ratio) of 2:1 A-3a, A-3b, or A-9c emission: 8 kw peak envelope power

TUBE COMPLEMENT
RF stages		AF stages and modulator		Rectifiers
Number	Type	Number	Type	Number	Type
2	3X2500A3			6	4B32
1	4-400A			4	3B28
2	807
1	6AG7

THIS TYPE OF TRANSMITTER IS INSTALLED IN THE FOLLOWING COUNTRIES
	ITU	Country	ITU	Country
	PHL	PHILIPPINES